A novel approach to investigate the synergistic inhibition effect of nickel phosphate nanoparticles with quaternary ammonium surfactant on the Q235-mild steel corrosion: Surface morphology, electrochemical-computational modeling outlines

Abstract

Novel quaternary ammonium Surfactant, namely, N,N-dimethyl-N-(3-((2-nitrophenyl)sulfonamido)propyl)dodecan-1-aminium iodide (QAS-12) has been prepared and characterized. The inhibition performance of the individual QAS-12 surfactant and blended with nickel phosphate nanoparticles (NiPNPs) in 15% HCl on the Q235-mild steel was investigated by means of EOCP-t profiles potentiodynamic, LPR corrosion rate and EIS measurements. The findings display that the corrosion rate of Q235-mild steel is considerably decreased with rise in the surfactant dose where the protection power of QAS-12 extents a maximum value of 93.1% at 0.5 mM. Synergistic protection effect was detected between the cationic QAS-12 and the NiPNPs additives, with the maximum protection capacity as high as ~98.6%. The adsorption behavior obeyed the Langmuir isotherm model with competitive of physical and chemical adsorption between the surfactant and metal. The individual surfactant and mixed with NiPNPs performed as mixed type inhibitors. Surface morphology analysis using XPS, SEM/EDX, and UV–vis absorption studies verified the high efficiency of the cationic surfactant on the inhibition of Q235-mild steel in 15% HCl solution, and the synergistic effect on corrosion protection among the QAS-12 and the NiPNPs was confirmed. Correlation of Computational Modeling with empirical findings of the current work is discussed based on the DFT calculations and MC simulation. The proposed mechanism for the synergism resulting from both addition of the cationic surfactant and NiPNPs was also discussed according to the obtained outcomes.